Transfer Case Fluid 2004 GMC Envoy

Does anybody know what fluid is available for a 2004 GMC Envoy transfer case? The Owner’s manual calls for “Auto-Trak II” GM part # 12378508. The local parts store did not have information on an equivalent lubrication. Also how much is needed for refill when just changing the fluid?


Most GM transfer cases used to all take regular old Dexron transmission fluid.

Unfortunately, many of the new ones require this “Auto-Trak” stuff. From what I’ve heard, if you try to substitute trany fluid in its place you may burn up the t-case. The only place to get it is the dealer.

I’m not sure what the fluid capacity is, but the dealer should be able to tell you when you buy the fluid.

In the big picture, how much money will you save by getting fluid at the parts store? Will you be sure it’s the right stuff? Are your drl’s still shining bright, by the way? P.S: If there’s a check plug that’s where you fill fluid to, (cold fluid to just below check hole.)

Yes and thanks, Karl. The DRLs are working just the way they used to before the failed sealed beam. And yes, I did go to the dealership and purchased three (at their recommendation) quarts of transfer case lube for the Envoy. I found that is the only place to get the recommended fluid. I am planning on changing the transfer case, differential and transmission fluids as well as the coolant. From what I have read, this should be done around the 40,000 mile interval.